%Checks to see if the robot is lost. The robot is considered lost if the
%weighting, pre-normalisation, of the biggest particle is smaller than some
%threshhold.
%Returns 1 if it is, 0 otherwise.
function lost = is_lost(particle_weight)
    lost_thresh = 0.1; %TODO: Tune this.
    if particle_weight < lost_thresh
        lost = 1;
    else
        lost = 0;
    end
    return
end